Recently, a technology of dissolving gas at a high concentration, or allowing gas to remain as air bubbles, be destroyed, or be floated in a liquid has been variously applied in several industrial fields including a food industry field.
Particularly, in a food field, gas such as carbon dioxide, or the like, is dissolved or allowed to remain in drinking water to thereby be utilized as a functional drink, or the like, in a semiconductor manufacturing field, air bubbles have been used to wash a surface of a semiconductor by allowing the air bubbles air bubbled in a liquid to be destroyed on an etching surface of the semiconductor, and in an environmental field, air bubbles having levitation power have been utilized in order to remove floating materials in waste water.
However, since the air bubbles used in various fields as described above should be manufactured so that air bubbles having a size suitable for purpose in each of the fields are contained, and the number of contained air bubbles also is suitable for the purpose, a different apparatus and method of generating air bubbles have been used in each of the field.
FIG. 1 illustrates an apparatus of generating air bubbles using a hydrodynamic method, which is a representative commercialized means among the existing apparatus of generating air bubbles.
Referring to FIG. 1, the apparatus of generating air bubbles is configured to include an underwater motor connected to an electric cord supplied with power from the land; an impeller formed at an output rotation axis of the underwater motor in a radial shape when being viewed from a bottom surface so as to finely crush air bubbles having a large diameter, and including a plurality of rotating blades having a jaw and formed in a saw-teeth shape; an impeller protection member including a partition wall provided with slits at a lower end of the underwater motor and extended downwardly so as to enclose the impeller, and a single-side filter having a cup shape and covered on a lower end of the partition wall; and a gas injector including a gas injection hose supplied with compression air from a compressor on the ground and connected to the underwater motor and a gas injection hose connected to a distal end of the gas injection so that a spray nozzle is positioned at the center of the impeller.
In the apparatus of generating air bubbles according to the related art as described above, fine air bubbles were formed in water by finely crushing oxygen introduced from the outside in a liquid using the impeller rotating at a high speed, but in order to rotate the rotating blades or impeller as described above at the high speed, a large amount of electrical energy is continuously consumed, and there is a problem in working safety.
Further, structures of water and oxygen molecules may be destroyed due to high-speed rotation of the impeller, and there are disadvantages such as mixing of metal particles due to abrasion of the rotating blade, a temperature rise of a fluid due to friction between the liquid and the impeller and heat of a driving motor, alternation of the fluid caused by the temperature rise, a decrease in the number of remaining air bubbles, and the like.
As a result, the apparatus of generating air bubble according to the related art as described above may be used only in some environmental field, for example, a case of floating the floating materials in waste water treatment, but uses of the apparatus of generating air bubbles are restrictive in fields requiring hygiene cleanliness such as a drink water field, a semiconductor washing field, or the like.
A necessity for a device and a method for adjusting the number and size of air bubbles, not causing a change in molecular structure of water or gas, which is the disadvantage of the apparatus of generating air bubbles according to the related art as described above, and not causing a phenomenon that foreign materials are contained, that is, not using the high-speed impeller has been increased.